Domain Switching and Energy Harvesting Capabilities in Ferroelectric Materials

This paper deals with the understanding of depolarization mechanisms in ferroelectric materials and how to improve energy harvesting by converting thermal or mechanical energy into electrical energy. Depolarization mechanisms caused by temperature were studied using X-ray diffraction (XRD) to describe the evolution of the domain organization. Polarization variations, constituting the key parameter for energy harvesting, were simulated from the XRD data and explained in terms of domain switching, variation of the dipole moment, and rotation of the dipole. The latter concerned structural transitions induced by an excitation and gave rise to significant nonlinearities in the material properties. Energy harvesting should combine two excitations (e.g., temperature and electric field, or stress and electric field) describing intelligent thermodynamical cycles. Various examples have been given to illustrate the possibilities for harvesting energy.